syzbot


KCSAN: data-race in __fsnotify_parent / __fsnotify_recalc_mask (3)

Status: auto-obsoleted due to no activity on 2023/12/25 00:07
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+237d89544930e1cab55e@syzkaller.appspotmail.com
First crash: 195d, last: 195d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __fsnotify_parent / __fsnotify_recalc_mask (4) fs 2 32d 60d 0/26 moderation: reported on 2024/03/20 10:08
upstream KCSAN: data-race in __fsnotify_parent / __fsnotify_recalc_mask fs 1 526d 526d 0/26 auto-obsoleted due to no activity on 2023/02/11 07:53
upstream KCSAN: data-race in __fsnotify_parent / __fsnotify_recalc_mask (2) fs 1 261d 261d 0/26 auto-obsoleted due to no activity on 2023/10/05 20:31

Sample crash report:
EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000.
==================================================================
BUG: KCSAN: data-race in __fsnotify_parent / __fsnotify_recalc_mask

write to 0xffff8881001c4ba4 of 4 bytes by task 3086 on cpu 1:
 __fsnotify_recalc_mask+0x204/0x300 fs/notify/mark.c:174
 fsnotify_recalc_mask fs/notify/mark.c:191 [inline]
 fsnotify_add_mark_locked+0x9c8/0xbd0 fs/notify/mark.c:730
 fsnotify_add_inode_mark_locked include/linux/fsnotify_backend.h:784 [inline]
 inotify_new_watch fs/notify/inotify/inotify_user.c:621 [inline]
 inotify_update_watch fs/notify/inotify/inotify_user.c:648 [inline]
 __do_sys_inotify_add_watch fs/notify/inotify/inotify_user.c:787 [inline]
 __se_sys_inotify_add_watch+0x66b/0x820 fs/notify/inotify/inotify_user.c:730
 __x64_sys_inotify_add_watch+0x43/0x50 fs/notify/inotify/inotify_user.c:730
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff8881001c4ba4 of 4 bytes by task 3123 on cpu 0:
 fsnotify_event_needs_parent fs/notify/fsnotify.c:161 [inline]
 __fsnotify_parent+0x128/0x480 fs/notify/fsnotify.c:202
 fsnotify_parent include/linux/fsnotify.h:77 [inline]
 fsnotify_file include/linux/fsnotify.h:100 [inline]
 fsnotify_close include/linux/fsnotify.h:342 [inline]
 __fput+0x1da/0x630 fs/file_table.c:380
 __fput_sync+0x44/0x50 fs/file_table.c:475
 __do_sys_close fs/open.c:1590 [inline]
 __se_sys_close+0xfa/0x1a0 fs/open.c:1575
 __x64_sys_close+0x1f/0x30 fs/open.c:1575
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x00000000 -> 0x00002008

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 3123 Comm: syz-executor.4 Not tainted 6.6.0-syzkaller-14614-g77fa2fbe87fc #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
==================================================================
EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000.
EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000.

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/06 01:24 upstream 77fa2fbe87fc 500bfdc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __fsnotify_parent / __fsnotify_recalc_mask
* Struck through repros no longer work on HEAD.